AQA A Level Physics Paper 3 Section A (2025-2026) Complete Exam with
Questions and Answers
A steel bar is clamped at the edge of a lab bench. The free end of the bar bends down with
deflection y. Outline an accurate method of determining y, the vertical deflection of the beam,
using a metre rule and any other equipment. - ✔✔✔-Clamp a ruler using a stand and a set
square to ensure the scale is vertical. Measure the level of the bar with no load and find the
difference in the level for the loaded bar, with eye level to minimise any parallax error.
From A level MS:
at least one instance seen where a metre ruler is made vertical using a set-square in contact
with the floor
strategy: (use a metre ruler to) measure the height of the free end of the tape (above the floor)
and the height of the tape at the bench [height of the bench]; y = difference between these
heights
OR use a metre ruler or straight edge placed alongside the tape measure and overhanging the
(horizontal) bench
y is measured directly using this method using additional ruler
using additional ruler made vertical (as before) or using set-square placed against horizontal
ruler
An equation is given and a student is asked to find the value of a constant term in the equation.
Explain what the student could do to find this constant [typical 5 marks]. - ✔✔✔-- State
independent and dependent variables.
- State the control variables.
- State any relevant measurements and measuring instruments.
- Suggest a valid graph to be plotted.
, AQA A Level Physics Paper 3 Section A (2025-2026) Complete Exam with
Questions and Answers
- Manipulate the equation of the graph to find the desired quantity.
Describe a suitable procedure a student should carry out to make sure measurements taken
using a micrometer or vernier caliper are not affected by systematic error. - ✔✔✔-close jaws
using ratchet
confirm that instrument reads zero
Describe how a mirror can be used to reduce parallax error. - ✔✔✔-A mirror can be used to
minimise parallax error when determining where a pin lines up with a scale. This is done by
lining up the pin with its own reflection and then taking a measurement. This is particularly
useful when reading analogue meters.
Describe two adjustments a student could make to reduce the uncertainty in measuring the
length of a vertical line on an oscilloscope trace. - ✔✔✔-Use x-shift to reposition trace so that
the end of the line is aligned with a horizontal graduation.
Use y-shift to reposition the trace so that the line is aligned with the central graduation on the
screen.
Discuss one possible advantage and one possible disadvantage of using a thinner beam/wire in
an experiment? - ✔✔✔-Same load produces larger values of deflection/extension, so
percentage uncertainty reduced.
May undergo plastic deformation, so graph will be non-linear.
May break, which could cause injury. It also means we won't be able to get data for unloading.
Questions and Answers
A steel bar is clamped at the edge of a lab bench. The free end of the bar bends down with
deflection y. Outline an accurate method of determining y, the vertical deflection of the beam,
using a metre rule and any other equipment. - ✔✔✔-Clamp a ruler using a stand and a set
square to ensure the scale is vertical. Measure the level of the bar with no load and find the
difference in the level for the loaded bar, with eye level to minimise any parallax error.
From A level MS:
at least one instance seen where a metre ruler is made vertical using a set-square in contact
with the floor
strategy: (use a metre ruler to) measure the height of the free end of the tape (above the floor)
and the height of the tape at the bench [height of the bench]; y = difference between these
heights
OR use a metre ruler or straight edge placed alongside the tape measure and overhanging the
(horizontal) bench
y is measured directly using this method using additional ruler
using additional ruler made vertical (as before) or using set-square placed against horizontal
ruler
An equation is given and a student is asked to find the value of a constant term in the equation.
Explain what the student could do to find this constant [typical 5 marks]. - ✔✔✔-- State
independent and dependent variables.
- State the control variables.
- State any relevant measurements and measuring instruments.
- Suggest a valid graph to be plotted.
, AQA A Level Physics Paper 3 Section A (2025-2026) Complete Exam with
Questions and Answers
- Manipulate the equation of the graph to find the desired quantity.
Describe a suitable procedure a student should carry out to make sure measurements taken
using a micrometer or vernier caliper are not affected by systematic error. - ✔✔✔-close jaws
using ratchet
confirm that instrument reads zero
Describe how a mirror can be used to reduce parallax error. - ✔✔✔-A mirror can be used to
minimise parallax error when determining where a pin lines up with a scale. This is done by
lining up the pin with its own reflection and then taking a measurement. This is particularly
useful when reading analogue meters.
Describe two adjustments a student could make to reduce the uncertainty in measuring the
length of a vertical line on an oscilloscope trace. - ✔✔✔-Use x-shift to reposition trace so that
the end of the line is aligned with a horizontal graduation.
Use y-shift to reposition the trace so that the line is aligned with the central graduation on the
screen.
Discuss one possible advantage and one possible disadvantage of using a thinner beam/wire in
an experiment? - ✔✔✔-Same load produces larger values of deflection/extension, so
percentage uncertainty reduced.
May undergo plastic deformation, so graph will be non-linear.
May break, which could cause injury. It also means we won't be able to get data for unloading.
